class Component():
    def init(self):
        pass

    def doSelectedKey(self):
        pass

class Keyboard(Component):
    def getSelectedKey(self):
        pass

class ActionKeyboard(Keyboard):
    def getAction(self):
        print ("请输入你的目的地！")

class TicketKindKeyboard(Keyboard):
    def getTicketKind(self):
        print ("请输入你的车票种类！")

class DestinationKeyboard(Keyboard):
    def getDestinationCode(self):
        pass

class Screen(Component):
    def showText(self):
        pass

class CardDriver(Component):
    def getCredit(self):
        pass

    def debitFare(self):
        print ("显示信用卡余额！")

    def ejectMCard(self):
        print ("显示扣除后的余额！")

class CashSlot(Component):
    def getCredit(self):
        pass

class Printer(Component):
    def printTicket(self):
        print ("纸质票据正在打印中！")

    def ejectTicket(self):
        print ("正在出票中！")

class TicketSoldSystem(ActionKeyboard,TicketKindKeyboard,DestinationKeyboard,Screen,CardDriver,CashSlot,Printer):
    def verifyCredit(self):
        pass

    def calculateFare(self):
        pass

people=TicketSoldSystem()
people.init()
people.getSelectedKey()
people.getAction()
people.getTicketKind()
people.getDestinationCode()
people.showText()
people.getCredit()
people.debitFare()
people.ejectMCard()
people.printTicket()
people.ejectTicket()